The small animal core will provide a centralized facility for the measurement of pulmonary resistance and compliance in anesthetized and ventilated mice, and for the measurement of responsiveness to intravenous acetylcholine. The core will also assist in broncholeveolar lavage and in the inflation, perfusion, and embedding of mouse lungs. The core facility will be equipped with two complete plethysmographic systems, including plethysmographs, pressure transducers, amplifiers, pulmonary mechanics analyzers, and chart recorders, and will be staffed by a full time staff research associate under the direct supervision of the principal investigator. The core will be extensively utilized by 4 of the 6 projects in this proposal, and the existence of a core facility will insure both quality control and rapid dissemination of technical information among these 4 projects. By utilizing existing equipment, and a newly constructed, dedicated small animal laboratory, this centralized facility will obviate the needs to train additional personnel in each project lab, to duplicate expensive equipment, and to set aside space in each laboratory suitable for experiments with live animals.